1. Field of the Invention
The present invention relates to fiber optic connectors for coupling radiation from radiation sources into waveguides; and more particularly it refers to connectors for coupling a laser device with optical fibers.
2. Invention Disclosure Statement
Connectors for coupling radiation from radiation sources into waveguides are meant for transmitting radiation with the main concern of reducing potential losses of radiation as much as possible. Losses of radiation in the interconnection between radiation sources and waveguides lead to a limited performance of the system reducing its overall efficiency and may provoke damage or destruction of the waveguides and/or the connectors.
There are different reasons for light losses which may occur during transmission of light signal during the interconnection process between radiation sources and waveguides. The amount of power delivered from a radiation source into a waveguide depends on the optical properties of both the radiation source and the waveguide. In general, the coupling loss of fiber optic connector results from poor fiber alignment and end preparation, fiber mismatches, and Fresnel reflection. As there is little of control over coupling loss resulting from fiber mismatches which are inherent fiber properties, fiber alignment renders as one of the critical parameters in maintaining low the total coupling loss. Hence, one of the main objectives when designing an optical connector is to reduce the amount of optical power lost at fiber optic connections mainly by maintaining fiber alignment and proper sizing. Good coupling efficiency requires precise positioning of the fiber to center the core in the focused laser beam.
To overcome the disadvantages of prior art connectors, a tunable fiber optic connector and method for assembly is disclosed in U.S. Pat. No. 6,695,489 by Nault. The connector includes a ferrule that is retainably engaged within a hub; a rear housing; and a front housing. The rear housing is sized to receive and rotationally retain the hub and the front housing has a bore that receives and engages the exterior surface of the rear housing. The front and rear housing include engagement members that allow the rear housing to be retained within the front housing and rotated relative to the front housing between discrete positions. However it differs from present invention as the tunable property is between the front and rear housings and the relative movement is a rotation movement.
Another example of fiber optic connectors for coupling laser energy into optical fibers, and more specifically into small core fibers, is disclosed in US patent application publication No. 2008/0175539 by Brown. It discloses a termination arrangement bearing a transparent ferrule fused to an end of an optical fiber to increase the coupling area without altering the input numerical aperture of the fiber system, accomplished by controlling the length of the area at which the transparent ferrule is fused or welded. In addition, an extended ferrule portion is situated behind the fusion area and is separated from the fiber core such that light that fails to couple to the core is reflected from the inner diameter of the extended ferrule portion away from the fiber core, where it can be deflected or dissipated by a beam block or absorptive material.
However, there is still a need for an improved and efficient device for linking radiation sources into waveguides, and more specifically medical devices and optical fibers in order to enhance the efficiency of the laser system and the delivery of laser energy to the tissue in a safe and efficient and cost-effective manner in medical applications. The enhanced device should be safe, easy to assemble, cost effective, and reliable in comparison with prior art devices, while allowing an effective coupling and efficient delivery laser energy to tissue. Present invention addresses these needs by providing compact, simple, reliable, safe and cost effective connectors.